[C++] Add simpler static ctor for BufferOutputStream than the current Create function #23066
Description
Not a major rough edge but the current Create function strikes me as a bit awkward since a size and memory pool must be explicitly passed
Reporter: Wes McKinney / @wesm
Assignee: Antoine Pitrou / @pitrou
PRs and other links:
Note: This issue was originally created as ARROW-6724. Please see the migration documentation for further details.